雙通道機載合成孔徑雷達於平台擾動效應下 對地面運動目標之成像

Abstract

本論文提出了一種雙通道機載合成孔徑雷達(SAR)成像方法，並補償平台軌跡偏差來獲取地面運動目標的圖像，聚焦效果良好。歸因於平台軌跡偏差或目標運動的相位誤差各由一個慢時間多項式表示。將運動補償前的SAR圖像分割成多個子圖像，並應用壓縮感知技術對每個子圖像估計平台軌跡偏差的多項式係數。再結合距離頻率逆轉換 (RFRT) 和分數傅立葉轉換 (FrFT) 以估計每個運動目標的運動參數和位置。所提出的方法分別用真實數據和模擬數據驗證，聚焦圖像中的運動目標可準確地識別。

A dual-channel airborne SAR imaging approach is proposed to acquire well focused images of ground moving targets after compensating the platform trajectory deviation. The phase error attributed to either platform trajectory deviation or target motion is given by a polynomial of slow time. The SAR image before motion compensation is segmented into multiple sub-images, and a compressive-sensing (CS) technique is applied on each sub-image to estimate the polynomial coefficients featuring platform trajectory deviation. A range-frequency reversal transform (RFRT) and fractional Fourier transform (FrFT) are combined to estimate the motion parameters and position of each moving target. The proposed approach is verified with real data and simulated data, respectively, and the moving targets in the acquired image are well recognized.